1. Field of the Invention
The present invention relates to article carrying apparatuses.
2. Description of the Related Art
Conventionally, various types of article carrying apparatuses for lining up articles such as bulk components in rows while carrying them and supplying the articles one at a time have been proposed. Such apparatuses are generally called “feeders,” and various types of feeders exist, including vibration- and belt-type feeders, although vibration-type feeders are the most common. A vibration-type feeder is an apparatus for carrying an article placed on a carry section, which vibrates, by exploiting for example the phenomenon of relative sliding of the article with respect to the carry section.
One example of such a vibration-type feeder is a linear feeder that carries articles over a straight path. This linear feeder has, for example, a carry section for carrying an article and a cam device, and is configured such that the carry section is supported at the top of a plate spring installed vertically on either end of a housing serving as the base of the cam device and such that a cam of a cam mechanism provided on the housing and a cam follower provided in the carry section are engaged with each other. A driving force of the cam mechanism is input to cause a carry table to vibrate (i.e., carry out a reciprocating linear motion) in a predetermined direction, and thus the article on the carry section is moved in the predetermined direction.
The carrying mechanism of such a linear feeder is described below with reference to FIG. 16A to FIG. 16C. FIG. 16A is a diagram for describing forces that act on the article when the carry section moves from a first position toward a second position, FIG. 16B is a diagram for describing forces that act on the article when the carry section moves from the second position toward the first position, and FIG. 16C. is a diagram for describing the position of the article when the carry section has returned to the first position.
This feeder is provided with a carry section 410 that linearly restricts the carrying direction to a straight line, and the carry section 410 vibrates between the second position X2 and the first position X1 set respectively to the front and the rear in the carrying direction (hereinafter, this is also referred to as “reciprocating movement”). As shown in FIG. 16A, when moving toward the forward second position X2 during reciprocating movement, relative sliding of the article W with respect to the carry section 410 is inhibited so that the article W moves together with the carry section 410. On the other hand, as shown in FIG. 16B, when moving toward the rear first position X1, the article W slides relative to the carry section 410 and only the carry section 410 moves to the first position X1 while the article W remains at the forward second position X2. By repeating this reciprocating movement, as shown in FIG. 16C, the article W is fed forward with respect to the carry section 410 in small increments, thereby achieving carrying of the articles (see JP 2003-40424A, for example).
In the conventional linear feeder described above, carrying of the articles is achieved by causing the carry section to vibrate. Thus, vibration of the carry section also is transmitted to the housing via the cam mechanism, which serves as a driving section for causing the carry section to vibrate. In other words, even when the linear feeder has the ability to carry the articles properly, there is a risk that the articles may not be carried properly due to the housing vibrating. For example, when the linear feeder is placed on a table or the like having low rigidity, the vibration transmitted to the housing is amplified by the table and causes the linear feeder itself placed thereon to vibrate significantly, and thus there is a risk that the articles may not be carried properly. Moreover, there also is a risk that noise may occur due to vibration of the table or the housing.